temperaturemonitor.java

Java网络编程与分布式计算, 主要分析java网络各方面的编程, 提供许多实用安全

import java.rmi.*;
import java.rmi.server.*;

// Chapter 11, Listing 8
public class TemperatureMonitor extends UnicastRemoteObject implements TemperatureListener
{
	// Default constructor throws a RemoteException
	public TemperatureMonitor() throws RemoteException
	{
		// no code req'd
	}

	public static void main(String args[])
	{
		System.out.println ("Looking for temperature sensor");

		// Only required for dynamic class loading
		//System.setSecurityManager ( new RMISecurityManager() );

		try
		{
			// Check to see if a registry was specified
			String registry = "localhost";
			if (args.length >=1)
			{
				registry = args[0];
			}

			// Registration format //registry_hostname (optional):port /service
			String registration = "rmi://" + registry + "/TemperatureSensor";

			// Lookup the service in the registry, and obtain a remote service
			Remote remoteService = Naming.lookup ( registration );
			
			// Cast to a TemperatureSensor interface
			TemperatureSensor sensor = (TemperatureSensor) remoteService;
	
			// Get and display current temperature
			double reading = sensor.getTemperature();
			System.out.println ("Original temp : " + reading);

			// Create a new monitor and register it as a listener with remote sensor
			TemperatureMonitor monitor = new TemperatureMonitor();
			sensor.addTemperatureListener(monitor);
		}
		catch (NotBoundException nbe)
		{
			System.out.println ("No sensors available");
		}
		catch (RemoteException re)
		{
			System.out.println ("RMI Error - " + re);
		}
		catch (Exception e)
		{
			System.out.println ("Error - " + e);
		}
	}

	public void temperatureChanged(double temperature)
		throws java.rmi.RemoteException
	{
		System.out.println ("Temperature change event : " + temperature);
	}
}